The present invention relates to an articulating support strength member. More particularly, the field of this strut invention relates to a support member used inxe2x80x94but not limited toxe2x80x94the flexible coverings field with particular emphasis on marine canvas, vinyl and similar synthetic materials.
Additionally the field relates to an articulating knuckle insert compatible with industry standard marine grade structural tubing. Further, my field of invention relates to inserts at a strut joint which have an anti-pinch configuration for positively moving the bidirectional sleeve away from the folding joint and thus assuring freedom of folding without damage to related structure.
Certain terms are used to introduce and explain the background of the art and the invention; and, for convenience and completeness sake, such terms are summarized in this section. These terms are not meant to supersede the claims nor the definition of terms as defined within the four corners of the specification; but, rather, are meant to further the understanding of the invention and briefly introduce the technical art stage for a detailed teaching of the improvement in the art as provided by this invention as claimed.
Locking Sleeve
A slidable tubular sleeve of an internal diameter a few thousands of an inch or so larger than the external diameter of its strut strength member counterparts. In rough weather a user may fail to completely slide the sleeve away from the folding strut section, and by gravity or weather such sleeve may become lodged and pinched at the strut""s folding joint with sufficient applied leverage by the strength members so as to cause structural damage.
Latching Detents.
Spring loaded balls which protrude partially through holes in sectional members, of a support strut. These detents retain the locking sleeve in place over an articulating bridge, thus locking the strut in an extended and taut position. In some installations the detent may be located so close to a strut securing fixture that the sleeve will not completely clear the detent in the unlocked configuration, with the possibility of the sleeve slipping into the joint and causing strut and/or framework breakage.
Articulating Bridge.
A short, relieved and shaped bridge (sometimes referred to herein as xe2x80x9clinkxe2x80x9d) which is hinge-pin connected at each end to identical, mirror image socket insert hubs. This articulating bridge, in concert with flat-faced mating socket hubs, creates a double knuckle two axis, foldable joint. Such bridges of my invention have a novel shape that bears against and automatically expels the slidable locking sleeve away from the folding joint.
Inserts (Sometimes Called Double Knuckle Hubs)
Relieved and shaped, but generally cylindrical, hubs of a snug fit diameter which are inserted into and fixed by pins to one member of a foldable two member strut. Such hubs receive and house the ends of a bridge cross piece of a novel configuration so as to provide safe and sure foldability for the joined strut sections. The bridge cross piece is uniquely shaped so as to not only expel the locking sleeve away from the joint location but also to provide an installation stop within the insert. Providing such hub inserts with a raised shoulder and an interior snug fit allows the hub to generally have the same outer diameter as the associated tube into which it is housed. This insert shoulder also contributes to my improvement features.
Foldable Strut.
In mechanical terms, a strut is a brace fitted into a framework to add strength and rigidity. For this invention the term strut is generalized to include both structural legs of a rigid tubing strength member. A strut further includes a foldable joint which includes a double knuckle geometry that allows the two portions of the strut to fold upon itself, in one plane only, or unfold into a straight straight configuration where the strut will become locked by a sliding sleeve.
Such a locked strut becomes a single rigid structural support member with improved compressive load bearing strength by virtue of a bridge and abutting faces of opposed inserts. That single strut member, in turn, locks other struts or fixture points in place within separate articulating framework members. (See Collapsible Covering below as one example of such framework.)
Axes of Rotation.
This invention provides two axes of rotation within the double knuckle insert of the foldable strut. In usage my foldable strut cooperates with two additional points of rotation at the outboard ends of the two strut portions. These outboard axes of rotation, or pivot points, are also the structural connecting points to a collapsible, skeletal framework. When a folding strut is extended and sleeve locked in place, both outboard axes of rotation become fixed by triangular geometry.
Collapsible Covering.
A generic term which includes awnings, bimini tops, dodgers, and other stretched coverings usually but not limited to weather exposed applications. A marine covering, by design, is taut when fixed in place over a rigid framework, generally of cylindrical tubing construction.
In marine applications such a framework is often pinned for a forward collapsing, articulating motion, and when opened, is held upward and rigid by straps in tension in the prior art. This articulating framework is usually configured with one or more crossway structural bows which have been inserted through stitched sleeves in a canvas or vinyl covering.
Installation Play
In marine applications a bow may spread across the deck of a small craft to which it is attached and have supports associated with the bow and the rest of the craft""s weather covering. Installation of such struts requires a small amount of longitudinal over play to avoid any binding of the strut when the frame is being folded. This installation over play is sometimes referred to as xe2x80x9cwobblexe2x80x9d and is on the order of one-half an inch or so. Without some installation latitude, not only would the installation be difficult, but worse still the joint in certain geometries would have a tendency to bind during frame folding.
Bimini Top.
A canvas or synthetic covering stretched tautly over a skeletal framework. A temporary convertible covering usually positioned over an outside steering station on a powerboat or yacht.
Dodger.
A weather covering of canvas-like material stretched tautly over a curved, tubular framework on a dodger becomes a temporary convertible covering over the forward portion of a sailboat cockpit and affords weather protection to both the steering station and the companionway entrance. Given the more limited deck space of a sailboat compared to a power yacht, dodgers are shaped and fitted to attempt optimization of weather protection and entrance/egress.
Articulating struts are well known and find many uses. Often such struts are manufactured in place as part of a customized larger equipment piece. Typical examples abound in the aircraft, space and marine and recreational industry. Often such struts employ many moving parts and are unusually complex for whatxe2x80x94on the surface, or to a casual observerxe2x80x94is a seemingly simple and straightforward application. An aftermarket in these various technical disciplines exists, and such an aftermarket calls for field installable struts.
The marine recreation world, for example, broadly involves both sail and power boats. Such craft use canvas or synthetic fabric-covered apparatus extensively for protection from sun and rain. On power boats, these coverings are known generically as bimini tops and usually cover a substantial portion of a deck or outside steering station such as a flying bridge. Depending on weather conditions, these bimini tops are preferably foldable and collapsible, usually in a forward direction, such that an operator may raise or lower the covering for personal preference.
In the sailboat world, similar but smaller coveringsxe2x80x94called dodgersxe2x80x94are used in much the same general fashion as the bimini tops. Sizes and shapes vary from boat to boat depending on specific deck designs which dictate attachment configurations. Field installation is prevalent for such craft and require foldable and collapsible struts.
Turning now to the prior art, a search prior to the filing of the parent application revealed various patents which are only of peripheral relevance. Such patents are listed in the soon-to-issue parent and need not be repeated here.
During prosecution of the parent, the Patent Office cited a Webster""s dictionary definition (xe2x80x9cdetentxe2x80x9d) and the following patents: Rosane U.S. Pat. No. 5,217,315; Rankin U.S. Pat. No. 5,178,583; Kitamura U.S. Pat. No. 5,431,508; Miller U.S. Pat. No. 5,743,208; Pollen U.S. Pat. No. 5,803,104; Parson et al U.S. Pat. No. 4,865,064; Bolin et al U.S. Pat. No. 1,036,222 and Patchell U.S. Pat. No. 1,906,218. This art is listed for completeness sake and was clearly distinguished in the parent. Such art is believed to be of little relevance to the improvement structure described and claimed in this continuing application.
The present application covers a situation that develops when a bidirectional springless locking sleeve forms part of a foldable strut which is attachable at each end to strut-securing fixtures of a fixed-in-place covering such as a marine covering, an awning or the like. Such coverings often are subject to wind and nature""s violence and thus require a quick and sure manual collapse/deployment under adverse conditions. Even skilled users familiar with such coverings may fail to properly latch out the sliding bidirectional sleeve and structural failure become imminent.
Indeed, on a pitching marine craft in extreme weather, it seems as if there are not enough hands to either properly set up or collapse such a covering. What is here presentedxe2x80x94for the first timexe2x80x94is a new and improved offset insert for a pinned strut having superior strength, flexibility in the field, and self supporting rigidity together with installation convenience and versatility.
My novel insert and the resulting strut serves several functions including actingxe2x80x94in regards to a bidirectional sliding sleevexe2x80x94as an expelling or xe2x80x9ckick outxe2x80x9d structure. I provide anti-pinch assurance, stops for installation advantages and other benefits which greatly reduce the opportunity for system failure.
Briefly summarized, the folding strut of this invention includes a strong pivoting connection link that is snugly fitted within a pair of opposed hubs, which hubs are themselves internally mounted in the proximate ends of a pair of hollow tubes or strength members. This connection link (or bridge) is seated in cutout hub portions, where it is pinned off-center to the hubs. My hubs each have step down flanges and are sized to snugly fit internally at the ends of a pair of opposed hollow cylindrical strength members of the same outside diameter. My hubs have a face-to-face contact area and stops for a limited amount of installation wobble.
Two spring-loaded detent push buttons manually position and hold a slightly oversized tubular sleeve which slides in place along the tubes and hubs. When the tubes and sleeve are extended into a straight (non folded) position the sleeve locks them in place. Manually depressing one or the other of the spring loaded detent buttonsxe2x80x94and, sliding the oversized sleeve from either direction away from the hinged jointxe2x80x94allows the strut (and thus the two strength tubes) to fold back upon itself.
In some folding instances, the slidable locking sleeve could become caught at the knuckle/joint location as the strut folds upon itself; and if that xe2x80x9ccatchxe2x80x9d is not eliminated the leverage arms in the strut section may cause considerable structural damage. My invention contains novel hub structure with offset center links provided with an internal kick out feature which will safely expel the locking sleeve from the joint in the event of an accidental pinch configuration.
In one embodiment my expulsion (or xe2x80x9ckick-outxe2x80x9d) structure is on the link; and, in another embodiment, my expulsion structure is on a shaped central post portion of a shouldered hub insert, which post supports a pair of outside spaced links that sandwich a sleeve expelling contour of the center post. A raised peripheral shoulder on my insert hubs also contribute to the anti-pinch features of my invention. Pinch potential may be the result of an accident, oversight or error in usage.
My folding strut is readily installable with in-the-field tubing. An installer can go to a boat with a knuckle assembly, tubing and a tubing cutter and proceed with a custom installation. My double knuckle is designed as an stand alone insert assembly with mirror image load bearing faces. Such faces, when the strut is extended, bear against one another in compression. Foldable struts can be custom installed for stand alone windshields and folding hatch coverings.
Additionally, a hinge pin offset tends to make the extended strut strong and rigid. Such structure in combination with a bidirectional sliding locking sleeve which is positively expelled from the folding joint provides a highly improved and versatile anti-pinch strut.
My pre-assembled hinge consists of two opposing slotted and shouldered hubs with rounded slots centrally milled or injection molded in the opposed hub faces. These slots house a central connecting link that has mated rounded ends pinned for rotation at offset locations. A symmetrical protrusion at the longitudinal center of the link in the shape of a convex curvexe2x80x94ie., convex relative to the folding direction of the strutxe2x80x94bears against and thereby urges the slidable sleeve away from a pinch situation.
This convex curve provides both an installation stop to prevent pin breakage or potential sleeve crush during folding and an anti-pinching protection at the sleeve end. Thus, in this embodiment, the shape of the link itself assures that the sleeve will not become pinched or crushed during collapse/deployment of a covering formed with my improved strut system.
Additionally, in my injection molded central link inserts, I have provided a link with a deep rounded saddle which is recessed away from the opposed hub, and I have further provided a smooth rounded base at the bottom of the saddle. Such structure in operation in my improved strut develops a vertical xe2x80x9ckick-outxe2x80x9d force vector which urges the sliding sleeve away from any accidental sleeve pinching area.
When extended, the in-line link and hub slots are located along a longitudinal axis. The internally located hinge allows each tubular strut member to fold up to 90-plus degrees from its normal straight in-line position to a parallel side-by-side location when the strut is in a folded configuration. Hinge pins holding my bridge are offset from that longitudinal axis and serve as a convenient radius of curvature location. That location is also instrumental in providing a hub with a unique rounded center post that provides anti-crush, anti-pinch and pin protecting features as further explained in more detail hereinafter.
It is a object of the invention to provide a rigid structural joint member between two tubular bows pinned at either end and provided with anti-pinch movements and structure.
It is an object of the invention to provide an articulating knuckle having an anti-pinch link joining two strength members in a foldable strut.
It is an object to provide an articulating knuckle with two pivot points holding a connecting link having a shape which includes a convex central portion acting as a stop and a sleeve expelling surface.
It is an object to provide a convex-shaped knuckle with two pivot points which is constrained to articulate in only one plane.
It is an object to provide a two point ant-pinch knuckle which has a freedom of motion from 0 to 180 degrees in one plane.
It is an object of the invention to provide a strut with a bidirectional slidable locking sleeve that will not become pinched at the folding joint.
It is an object of the invention to a provide an efficient lockable strut with a slidable sleeve cooperating with two spring loaded ball detents and joint structure which avoid sleeve pinching.
It is an object of the invention to use a material such as stainless steel for marine environment usage.
It is an object of this invention to allow collapsing and folding of marine coverings without removal of canvas and free of sleeve pinching at strut joints.
It is an object to provide a knuckle and locking sleeve of anti-pinch configuration, which structure is field installable.